The present invention relates to a beverage dispensing system and is especially concerned with a system for dispensing carbonated beverage where carbonation is effected within the system by absorption of carbon dioxide (for convenience hereinafter referred to as CO2) within a liquid for the beverage.
Carbonated beverage dispensing systems are well known for dispensing on demand so-called soft drinks where the beverage is derived in the system by mixing beverage syrup or concentrate with water. Two such systems are known of which the preferred is a so-called "post mix" system where water is first subjected to CO2 gas and the resulting carbonated water mixed with the syrup as the beverage is dispensed. The second system is a so-called "pre-mix"system where water and syrup are first mixed to form un-carbonated beverage and such beverage is subjected to CO2 gas for dispensing as the carbonated beverage. Many beverages, typically soft drinks such as lemonade, colas and the like and fermented beverages such as beer, cider and the like, are carbonated to improve their flavour and mouth feel characteristics and also their aesthetic qualities such as sparkle and head or froth formation. It is recognised that to achieve their preferred characteristics, different beverages require different quantities of CO2 absorbed therein. Typically carbonated beer will have a CO2 content in the range of 4 to 4.4 grammes per liter (above this range it is likely that the liberation of CO2 from the beer during dispensing will create excessive and inconvenient frothing and below this range it is likely that the beer will be unacceptably flat) whereas lemonade and similar soft drinks will usually have far greater weights of CO2 absorbed per liter (usually they will have as much CO2 absorbed therein as is practical to provide excessive effervescence and sparkle). As a consequence of the aforegoing it has been found that known carbonation systems for dispensing beverage on demand are unsuitable for use with beverages when there is a requirement for a relatively low level and consistent content of absorbed CO2 to be maintained in the beverage as dispensed and it is an object of the present invention to provide a beverage dispensing system which satisfies this requirement.